The thing with this set and rattle cage is,you need jewels and weps otherwise you lose out on the undaunted passives. I run rattlecage and tbs and it's OK.
The purple drop rate is so low, specially for the necklaces. I have spent tons of champion points etc. to get better quality loot and it doesn't seem to help much.
channeled ability is anything that takes time to do the ability, so jabs, radiant destruction as you asked, as well as skills like snipe, wrecking blow, soul ultimate, ect.